/*
 * Copyright (c) 2010, Tangedyn <tangedyn at gmail.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   * Neither the name of the Mew Developers nor the
 *     names of its contributors may be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

package yawning.mew;

public class Report {
	private double mPerformanceSum;
	private double mPerformanceSquare;
	protected int mIterations;

	public void setPerformance(double v) {
		mPerformanceSum = v;
		mPerformanceSquare = v * v;
		mIterations = 1;
	}

	public double getPerformance() {
		return mPerformanceSum / mIterations;
	}

	public double getStdDev() {
		double mean = getPerformance();
		return Math.sqrt(mPerformanceSquare / mIterations - mean * mean);
	}

	public double getStdError() {
		return getStdDev() / Math.sqrt(mIterations);
	}

	public int getIterations() {
		return mIterations;
	}

	public Report accumulate(Report r) {
		mPerformanceSum += r.mPerformanceSum;
		mPerformanceSquare += r.mPerformanceSquare;
		mIterations += r.mIterations;
		return this;
	}
	
	public String toString() {
        return "Performance: " + getPerformance() + " ±" + (getStdError() * 1.96) + "\nStandard Deviation: " + getStdDev() + ")";
	}
}
